"Its very strange at first, serious nightmares, its almost like lucid dreaming, very 3D, and you have more ability to make decisions in the dream.  It takes me at least 2 hrs for it to work, and I have taken it and stayed in bed for hours with a horrible nights sleep.  It works different than ambien, it gives me a sedative feel.  Make sure you have at least 7 hrs to sleep.  Once you get used to it, the negative side effects I think go down.  The half life is longer than Ambien and that's good but it still does not have the effect of a quick acting sleep med.  More expensive too because its new and there is no generic yet."